首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   59篇
  免费   0篇
化学工业   10篇
金属工艺   1篇
机械仪表   2篇
建筑科学   9篇
轻工业   4篇
石油天然气   2篇
一般工业技术   4篇
冶金工业   23篇
自动化技术   4篇
  2022年   4篇
  2021年   4篇
  2020年   1篇
  2019年   2篇
  2017年   1篇
  2016年   2篇
  2013年   2篇
  2011年   1篇
  2010年   4篇
  2008年   1篇
  2007年   1篇
  2004年   1篇
  2003年   1篇
  2000年   1篇
  1999年   1篇
  1998年   3篇
  1996年   2篇
  1995年   1篇
  1994年   2篇
  1991年   1篇
  1987年   3篇
  1982年   1篇
  1981年   2篇
  1980年   2篇
  1977年   4篇
  1976年   7篇
  1975年   2篇
  1971年   2篇
排序方式: 共有59条查询结果,搜索用时 15 毫秒
1.
Conclusion Separation of martensitic transformation into several stages in martensitic corrosionresistant steels may be explained by a concentration gradient for carbon and carbide-forming elements in austenite as a result of precipitation of them during cooling.Spain. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 7, pp. 7–8, July, 1991.  相似文献   
2.
Refrigeration at dairy farms in Brazil would contribute substantially to improving the rate and quality of milk production. Farmers would be able to milk twice a day or more, and keep the milk refrigerated until it was transported to the delivery station. The 1980 rural electricity consumption in Brazil's major milk-producing state was only 0.93% of the national total2. This low consumption can be attributed to the high costs associated with the electrification of the rural regions. In these areas, cooling cycles based on the absorption principle may be especially suitable. Solar energy, coupled with methane generated from cattle herd wastes, has been investigated as a source of auxiliary energy.  相似文献   
3.
Internet data collection is becoming increasingly popular in all research fields dealing with human perceptions, behaviors and opinions. Advantages of internet data collection, when compared to the traditional paper-and-pencil format, include reduced costs, automatic database creation, and the absence of researcher-related bias effects, such as availability and complete anonymity. However, the validity and reliability of internet gathered data must be established, in comparison to the usual paper-and-pencil accepted formats, before an inferential analysis can be done. In this study, we compared questionnaire data gathered from the internet with that from the traditional paper-and-pencil in a sample of college students. The questionnaires used were the Maslach Burnout Inventory - Student Survey (MBI-SS), the Oldenburg Burnout Inventory (OBI-SS) and the Copenhagen Burnout Inventory (CBI-SS). Data was gathered through a within-subject cross randomized and counterbalanced design, on both internet and paper-and-pencil formats. The results showed no interference in the application order, and a good reliability for both formats. However, concordance between answers was generally higher in the paper-and-pencil format than on the internet. The factorial structure was invariant in the three burnout inventories. Data gathered in this study supports the Internet as a convenient, user-friendly, comfortable and secure data gathering method which does not affect the accepted factorial structures existent in the paper format of the three burnout inventories used.  相似文献   
4.
Effect of charcoal-broiled beef on phenacetin metabolism in man   总被引:1,自引:0,他引:1  
When charcoal-broiled beef was fed to human volunteers, who were then given phenacetin orally, the concentration of phenacetin in the plasma was lowered, but its half-life in the plasma was not changed. The data suggest that feeding charcoal-broiled beef enhances the metabolism of orally administered phenacetin in the intestine or during its first pass through the liver, or both.  相似文献   
5.
6.
The body's equilibrium is possible thanks to the integration of skeletal structure, vertebrae, ligaments and muscles to form one functional unity. The forces which determine posture are composed of two complementary systems, the ligamentary and the muscular systems, which together determine a dynamic act of balance. The ligaments operate mainly against the visco-hydraulic pressure of the nucleus pulposus and bind the vertebral bodies together, whereas the muscles exhibit an antigravity function and support spinal stability. A mathematical model based on a mixed theory of directed and oriented curves is proposed. Through this model it is possible to develop an exact theory governing the deformation of the ligamentous spine. This theory should be universal in the sense that it can be used to supply the spine in any of its environments.  相似文献   
7.
8.
The focus of this paper is to determine flammability characteristics of rubber materials that are common to vehicle tires, conveyor belts, and electrical power cable insulation and to compare the thermal magnitude of cargo quantities of these materials to other fuels that are publicly transported. Although a literature review was performed, very little data was found on this topic. Standard flammability test procedures were used to measure the critical flux for ignition, critical ignition temperature, and heat release rates (HRR) of rubber compounds common to tire tread materials and conveyor belt covers. Both the intermediate scale calorimeter: ISO 14696, ASTM E-1623 (ICAL) and the cone calorimeter: ISO E-5660, ASTM 1354 (Cone) provided the bulk of the data. Critical ignition flux and vertical flame spread data for rubber based electrical insulations were determined using a radiant panel from a modified ASTM flame spread apparatus: ASTM E-162. thermogravimetric analysis was also used to evaluate thermal decomposition progression of selected test materials. Further, suppression tests were conducted on tire piles to evaluate agents to extinguish and control tire fires. Also, the HRR of the tire piles were measured and compared to work performed by others. Results confirm that the area heat release rate of rubber materials is directly proportional to exposure flux intensity. The critical exposure flux for ignition of a variety of rubber-based materials is approximately 20 kW/m2 to 30 kW/m2 and the critical temperature for piloted and non-piloted ignition were independent of exposure intensity at ~400°C and ~600°C respectively. In large quantities, rubber tire loads have total HRR comparable to the heat released from similar areas of liquid hydrocarbon spills.  相似文献   
9.
10.
The enteric nervous system plays a role on the stimulation of secretory cells of intestinal epithelia. We have demonstrated that ablation of ENS stimulates epithelial cell proliferation. As goblet cells are important constituents of the epithelial sheet, it is mandatory to investigate separately this cell type. The myenteric plexus of the ileum of rats in postnatal development was partially removed by the serosal application of benzalkonium chloride (BAC). Three groups of animals were used: those where BAC application was at 13 days and sacrifice was at 15 (13/28-day-old) or 23 days after treatment (13/36-day-old), and those where BAC was applied at 21 days and rats were killed 15 days after treatment (21/36-day-old) . The number of goblet cells in the ileum was estimated in sections stained by periodic acid-Schiff (PAS) histochemistry. In the 13/28 and 21/36 groups, the number of goblet cells was significantly higher after BAC treatment. These results suggest that the myenteric denervation may have an acute effect on the number of goblet cell in suckling and weanling rats, probably through submucous plexus.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号